Heat sealing adhesive sheets or tapes



latented Mar. 17, 1953 HEAT SEALING ADHESIVE SHEETS OR- TAPES Max M. Kline, Raritan Township, Middlesex County, N. J., and Charles Olson Pike, Reno, Nev., assignors to Industrial Tape Corporation, a corporation of New Jersey No Drawing. Application June 21 1947, Serial No. 756,330

Claims. (01. 117-76) 1 This invention relates to heatsealing adhesive sheets or tapes. While not limited thereto it is particularly concerned with heatsealing adhesive sheets or tapes for use in mending all types of household fabrics, and laundry goods in general.

Adhesive sheets or tapes of the type under consideration have their chief utility in the mending and patching of fabrics, in the household, and in the commercial laundry. It is desirable that such products adhere to a wide variety of fabrics including those of cotton, linen, wool, viscose rayon, cellulose acetate rayon, synthetic fabrics such as superpolyamide, coated fabrics, impregnated fabrics, tightly woven material or loosely woven cheese or tobacco cloth and the like.

Sheets or tapes of the type contemplated by our invention are provided with a strong but in-. 1

expensive, flexible, usually porous, backing such as paper, coated paper, impregnated paper, cotton cloth (among woven materials those woven tighter than 50 square are usually preferred), coated cloth, impregnated cloth, nonfibrous film and the like. For the purposes of the invention, however,

.the type of backing is not important and any fabrics and household goods mended with heatsealing adhesive tape often undergo washing and drycleaning. In the case of fabrics not resistant to water or solvents the mend would be disturbed otherwise in places where the water or solvent removes or destroys the heatsealing adhesive bond. Various thermoplastic polymers have been preferred for use as heatsealers in this art.

Many heatsealing tapes of the proir art are based on vinyl chloride acetate copolymers. These adhesives are superior to all others of the prior art but have several important defects. They do not adhere satisfactorily to synthetic fabrics such as viscose or cellulose acetate rayon. They do not withstand repeated washings too well, and a mending patch will frequently come loose after but a few washings. In view of the temperature required for satisfactory sealing and in view of the heat which the patch should withstand during normal wear the softening point of the heatsealing adhesive has to be relativelyhigh. The high period be short otherwise the backing of the tape temperature in turn requires that the sealing or sheet or the fabric being mended may be burned. Prolonged heating would frequently cause the heatsealing adhesive to flow through the backing of the sheet or tape, soil the back side of the mending tape or sheet and make anunsightly and unsatisfactory mend. Where, on the other hand, --a polymer having too low a sealing temperature is provided, complete blocking may result and the finishedpatch again may be unsatisfactory because of the softness of the adhesive at normal temperature. Accordingly the patch-will come off easily even where the mended spot receives merely mild mechanical rubbing or mild rubbing in a washing machine or laundry. 1 a

In accordance withthe invention the adhesive sheet or tape has two substantial superposed layers in the heatsealing adhesive coat which, preferably, has a total coating weight of at least two and not more than seven ounces per-square yard. r In a preferred form of theinventiom-thesurface layer of the adhesive will be composed of a maleic modified soft vinyl chloride acetate copolymer having a relatively low melting point and a relatively high degree of cold flow. The preferred maleic modified copolymer, in accordance with the invention, is a member of the group consisting of the copolymers of more than percentby weight of vinyl chloride and less than 30 percent by weight of vinyl acetate. The maleic acid or anhydride modification shouldbe to the extent of 0.5 to 5 percent of maleic acid based'on the weight of the copolymer. --We havefound that adhesion to a'great'variety of surfaces is obtained where an unusually soft copolymer, say one comprised of substantially'86 percent vinyl chloride, 13 percent vinyl acetate and 1 percent maleic acid, is employed. The more vinyl chloride is present in the composition the higher a viscosity, molecular weight and melting point willbe obtainable in the copolymer; In applicants preferred range the polymer is fairly soft, has a low melting point and is quite'weak.

The weakness of the polymer, if the copolymer were used alone, Wouldaccount for a weak final bond which in turn would'cause poor laundering and unsatisfactory wear of fabrics; Suprisingly we have been able to provide a completely satisfactory bond which will wash, dryclean and wear well and yet adhere satisfactorily to almost-any surface by application of a high strength polymer coat between the backing and the adhesive surface cost. This polymer should be compatible with the surface adhesive layer when a"melt thereof is mixed therewith. Compatibility can readily be ascertained by simple visual observation of the blend. If the two polymers blend readily or react to blend readily and appear homogeneous there is compatibility; if they tend to separatewhen heated? or dissolvedin mutual solvents they are incompatible and unsuitable in our invention. lower adhesive layer should have a softening pointmore than 20 and less than 100 F. higher than that of the top surface layer. point differential would cause the underlying layer to sink into its own backing at the effect-ivesealing temperature of the top layer andwould thus provide an insufficient effective bonding layer. Moreover, the fabric backing would be too much stiffened due to penetration by thelower bonding layer and would thus provide an unsatisfactory mend. Such a mend would have an, irritating feel and insufiicient flexibility for proper handliilg V and wear.

.If the softening point differential is too high, the, lower layer will not soften at the heatsealing temperature of the top layer. Accordingly the lower layer will not blend sufficiently with the top layer and will not provide the unified structure andsecure bond which would not separate into two layers. Moreover, in view of the absence of blending between the two layers, the top layer would still be too weak and have not enough reinforcement from the lower layer. Using the structure of the invention, however, it is possible to obtain satisfactory blending'between the two ad- -jacent layers providing suflicient mutual anchorage and satisfactory reinforcement of the weaker 7 low softening layer.

adhesive layer providing body and strength to 'said heatsealing adhesive layer. A flexible backing is provided under this higher softening layer. I The lower layer may be composed of any polymer material provided it comes within the specifie'd softening point differential range and is compatible with the surface adhesive coat as specified above. Suitable undercoats within the above specification maybe made readily from various vinylchloride-acetate copolymers, polyvinyl choride, vinylidene chloride-vinyl chloride copolymers, polyvinyl chloride-acetate, butadiene-acrylonitrile copolymers having an excess by weight of butadiene, mixtures of the above recited polymers and copolymers, and in fact in view of the physical, rather than chemical nature of this phase of the invention, of any other composition coming within the specified limits of physical properties. Each layer or group of layers should comprise at least 25 percent of the total coating weight in the heatsealing mending tape.

-Where adhesion to a wide variety of surfaces is not so important, of course, it is always possible to make a satisfactory adhesive product using any heatbonding surface coat which comes within the specified softening point differential and has sufiicient adhesion for the purpose instead of the maleic modified copolymer. In this connectionheatsealing compositions composed of lower softening vinyl chloride acetate copolymers as the vinyl chlorides, vinylidene chloride copolymers largely vinylidene chloride, methacrylate, polystyrene andmany other materials are known inthe art. Maleic modifications of these heat- In addition to compatibility the A lower softening,

sealers may be used. The important factors, as far as the invention is concerned is that the surface coatzand intermediate. coat. are: highly compatible with each other and that the required softening point differential exists. In view of the laundering requirements for the product it is desirableto have both the top and the under coat from materials which are resistant to repeated washings and to drycleaning solvents which are usually. straight aliphatic or aromatic or chlorinated hydrocarbons:

,Suitable plasticizers may be used to obtain the desired melting point differential. Where polyvinyl chloride; acetate copolymers are used the preferred plasticizers are dioctyl phthalate and also triglycol di-2-ethyl hexoate, although in fact many compatible plasticizers may be used. Among such compatible plasticizers there are:

=amyl phthalate, chlorinated diphenyl, butoxyate, ethoxydiglycol phthalate, ethylhexyl phthalate, ethyl phthalate, triglycol di-2-ethylbuyrate,

triglycol chlorhydrin phthalate, ethyl o-benzoyl benzoate, diglycol dipropionate, methoxyglycol acetylricinoleate, butoxyglycol phthalate, tricresyl phosphate, methoxyglycol phthalate, methoxyglycol sebacate, methoxyglycol stearate, methyl phthalate, phenolindene-coumarone" oil, phenyl phthalate, diphenyl-o-xenyl phosphate, tri-(ptertiary butylphenyl) phosphate, o--and p-toluene ethyl sulfonamides, o-cresyl-p-toluene sulfonate, ethyl phthalyl ethyl. glycollate, butyl phthalyl butyl glycollate, methyl phthalyl methyl glycollate, di-(methylcyclohexyl) adipate, tributyl citrate.

Other. usual compounding agents may be used with any and all ofthe polymer coatings to modify them as desired. Inert fillers may be added to cheapen the product or to color'or-reinforce it. Typical fillers which have been used to great success are zinc oxide, titanium dioxide, lead oxide, calcium carbonate, clay, magnesium carbonate. In the case of the vinyl chlorides and vinylidene chlorides,,,copolymers,some of which are not too stable chemically when heated, stabilizers may be added to provide higher stability.

Among suitable stabilizers are lead oxide and hydroxide condensation, products of urea, the aliphatic esters, of acetoxy chloride stearic. acids,

tertiary ethyl urea, forinstance tertiary amyl urea or tertiary butyl urea, phthalimicles, sulfoni mides such. as sodium sulfonimides and magnesium sulfonimide calcium ethyl acetal acetate,

lead stearate, lead oleate, diphenyl lead stearate, diphenyl lead oleate, tribenzyl leadstearate, tribenzyl lead oleate, tribenzyl lead ricinoleate, di-

phenyl tin oxide, diphenyl lead oxide, triphenyl lead stearate, triphenyl' basic tin stearate, ethyl benzidene, calcium stearate, and many others. Provision of such additions to vinyl or vinylidene copolymers or polymers is well known in the art and forms the subject of a wide list of patents Table of compositions used in the examples heatsealing [All parts are by weight] A B CDE ILGH I J K LM'N o P Q are Maleic Modified Vinyl Chloride Acetate Copolymer (82% vinyl chloride, 16.5% vinyl acetate, 1%% maleic acid; molecular weight 9,000) 1 v 70 74 67 Maleic Modified Vinyl Chloride Acetate Copolymer (86.3% vinyl chloride, 13% vinyl I acetate, 0.7% r maleic acid; molecular weight 7,000) .5 64 78 64 Vinyl Chloride Acetate Copolymer (85% vinyl chlo- .7

ride, vinyl acetate; molecular weight 10,000)... 37 32 32 37 31 Vinyl Chloride Acetate Copoly-rner (88% vinyl chloride, 12% vinyl acetate; molecular weight 13,000)-.. 25 33 32 31....

Vinyl Chloride Acetate Copolymer (90% vinyl chloride, 10% vinyl acetate; molecular weight 16,000)..- ,....1 25

Vinyl Chloride Acetate Copolymer (93%vinyl chloride, 7% vinyl acetate; molecular weight 22,,Q00).-..; 80 67 100 Vinylidene Chloride Vinyl Chloride Copolymer (major portions of vinyl chloride and vinylidene chloride extra high molecular weight, tough relai tively insoluble copolymer softening point 450 F.). $10 67.--- 100 Vinyl Acetate Polymer (Viscosity 60 centipoises when in molar solution in benzene) Butyl Methacrylate Polymer, Soft Alkyd Plasticizer (soit, high molecular weight, low

cross-linkage, soluble in esters and aromatics, nitrocellulose compatible acid number 1, Gardner-Holdt viscosity RU in 50% solution in ethylene dichloride lS Triethylene Trioctyl Phosphate. Basic Lead Carbona Stearic Acid Softening Point (F. Lowest P 446140 Softening Point (F.), Highest Point of Rang 1 All percentages and molecular weights are averages and approximate as closely as obtainable. All polymers are heat stabilized in one of the manners indicated earlier in'thisspecification.

These compositions may be applied to backcordance with the invention, for instance inthe ings to form heatsealing adhesive tapes in acfollowing examples:

Approximate E 1 Wtsin gulncesd Wtin guincesd g gig ig g' xamp e per q. an per q. an

No. Backmg Composition of Composition of {5533221 Surface Coat Base Coat Base and Surface ICoat (F.)

1---- 80 x 80 Cotton Cloth 2.0 of N 25 o 1.5 of 0 25 1.0 of P.. as 1.0 of Q 100 2.25 Of N 25 6 .-...do 2.25 of O 25 7.. 80 x 80 Cotton Cloth... 1.5 of P. 95 8-- o 1.5 oiQ. 100 9.. Finely Woven Nylon-.. 1.5 of N 25 10 ..do 1.5 010 25 11- 56 x 64 Cotton Cloth... 1.0 of P. 95 12. 80 x 80 Cotton Cloth..- 1.0 of Q. 100 13. 1.0 Of N. 25 14. 1.0 of O 25 15. .75 of P 95 16. -.-..do .75 of Q 100 17- Finely Woven Acetate Rayon. .75 of N '25 18. -....d0 .75 MO 25 19. 56 x 64 Cotton Cloth. .75 of P. 95 20. do .75 of Q 1'00 21. Finely Woven Nylon 1.5 of N. 25 22. Finely Woven Acetate Rayon. 1.5 of O. 25 80 x 80 Cotton Cloth 1.5 of P-... 95 d 1.0 of Q 100 1.0 of N 30 1.0 of O 20 1.0 of P... 100 1.0 of Q. 100 2.0 of N. 30 2. 0 of O. 2.0 of P-. 100 2.0 of Q. 100 1.5 of N 1.5 Of O 2O 1.5 of P. 100 do 1.5 Oi Q- 100 37-. Finely Woven Nylon 1.5 of G. 38.. 1.5 OIL. .5 of A- 0 .5 oi B 90 eas est Approximate E l Wtin ggncesd Wt.sin gincesd gg ggg iz' xamp e per q. an per q. an

N0. Backing Composition of Composition of :53:13; Surface Coat Base Goal: 7 Base and Su face Coat (F.)

41 Finely Woven Nylon .75 of C. 90 42 do 2.0 of D 90 43 Dead Soft Aluminum Foil 1.0 of E. 90 44 1.0 of F"..- 90 2.0 of R-- 0 2.0 of S. 60 2.0 of R 55 48 do 2.0 of S 55 49 Vinyl Film .75 Of L 60 r In general the compositions may be prepared in any suitable manner, for instance by mixing in an internal type mixer or on a rubber mill. Specific mixing procedures are not critical and will occur readily to those skilled in the art. Merely for illustrative purposes, however, typical mixing and coating procedures for use, for instance the one used in connection with Example A follows:

First the lower coat is prepared:

The vinyl chloride acetate copolymers are intimately worked on a hot rubber mill until substantial homogeneity is obtained. A mixture of the plasticizers and fillers is then added into the mill gradually so as to prevent cooling of the polymers. After all is added and the entire composition is uniform the coating may be applied to the backing by use of a calender or, alternatively, may be dissolved in an ester type solvent and coated on cloth by means ofa knife coater or a reverse roll coater. The amount of coating applied and type of coating may be regulated by adjustment of coating conditions, e. g. speed, viscosity of solution, etc. Care should be taken where cloth backings are used to prevent loss of effective adhesive film strength by disappearance of the adhesive film into the backing. Accordingly fairly viscous coating solutions or compositions should be employed, and in the case of calender coating, the calender should not be too hot.

The surface coat is made by dissolving the copolymer and the plasticizer in a solvent, e. g. .in a mixture of equal parts of toluene and methyl ethyl ketone or acetone. A solution comprising approximately 40 percent solids is prepared. This solution is then applied in any desired manner Ito the precoated side of the backing, for instance using a reverse roll coater. A satisfactory product results. a Usually in mending the fabric, a piece of the tape or sheet, somewhat larger than the repair to be made is rounded at the corners and placed with the coated side down, on the torn portion.

Heat and pressure are applied to the tape or sheet by a hot iron which is held in place for a short period (say '7 seconds) to soften the thermoplastic adhesive. The iron is then removed and the thermoplastic, upon cooling, forms a bond between the cloth part of the tape and the cloth of the garment or other item to which it has been applied. Hot iron mending tapes come in several basic colors in addition to black and white so that the user may match as closely as possible the color of the material to be repaired and render the repair as inconspicuous as possible. Alternatively the user may want to cut patterns out of the heat-sealing tape and apply them to a fabric background so as to ornament such background.

Wherever mention is made herein of softening points such softening points are determined in the following manner:

A film of the adhesive mass about 5 mils thick is cast on the surface of a suitable cloth backing, such as 80 x 80 cotton sheeting. The apparatus consists of an electric soldering iron which has been modified so that the heated block has a oneinch square smooth surface in place of the point. A very small hole is drilled into the block parallel to, and about 3 millimeters from the surface. The apparatus is mounted by means of clamps and a stand so that the surface is perpendicular and the needle of a pyrometer can be inserted in the hole from the side. A 1 x 2 inch piece of the sample to be measured is applied firmly to the surface by means of an electric iron so that it covers the surface and the extra inch hangs down. A clamp and weight, whose combined weight is 75 grams, is fastened to the hanging tab of cloth and the current to the apparatus turned on. The rise in temperature is observed by means of the pyrometer. The temperature readings are taken when the cloth begins to slide and when it falls off. These two temperatures are reportedas the range of the softening temperature.

All embodiments within the scope of this specification and/or the appended claims are comprehended. Having described these various embodiments of our invention for purposes of illustration rather than limitation, what is claimed is as follows:-

1. As a new article of manufacture, a mending sheet adapted for the repairing of torn surfaces by adherence thereto under the influence of heat and pressure, comprising in combination a flexible fabric base one surface of which is coated with a plurality of superimposed coatings, one of said coatings adhering to said base member as an undercoat, another of said coatings adhering to said undercoat and comprising a surface coat, said surface coat consisting essentially of at least about six parts by weight of vinyl chloride vinyl acetate copolymer including at least sixty five per cent by weight of vinyl chloride and from about ten to about thirty per cent of vinyl acetate; and of a minor portion, not exceeding about four parts by weight of the surface coat composition, of a compatible plasticizer; said undercoat consisting essentially of at least about six parts by weight of a vinyl chloride vinyl acetate copolymer including at least sixty-five per cent by weight of vinyl chloride and from about ten to about thirty parts by Weight of vinyl acetate;

and of a minor portion, not exceeding thirtysix per cent by weight of the undercoat, of a compatible plasticizer; said underccat being compatible with said surface coat and having a softening point between about twenty degrees Fahrenheit and about 100 degrees Fahrenheit higher than said surface coating.

2. As a new article of manufacture a mending sheet adapted for the repairing of torn surfaces by adherence thereto under the influence of heat and pressure, comprising in combination a flexible fabric base one surface of which is coated with a plurality of superimposed coatings, one of said coatings adhering to said base member as an undercoat, another of said coatings adhering to said undercoat and comprising a surface coat, said surface coat consisting essentially of at least about six parts by weight of a maleic modified vinyl chloride-vinyl acetate copolymer including at least about sixty-five per cent by ceeding about four parts by weight of the surface coat composition of a compatible liquid plasticizer; said undercoat consisting essentially of at least about six parts by weight of a vinyl chloride vinyl acetate copolymer, including about nine parts by weight of vinyl chloride, about one part by weight of vinyl acetate; and a minor portion, not more than about four parts of its weight of a compatible plasticizer; said undercoat being compatible with said surface coat and having a softening point between about twenty degrees Fahrenheit and about 100 degrees Fahrenheit higher than said surface coating.

3. As a new article of manufacture, a mending sheet adapted for the repairing of torn surfaces by adherence thereto under the influence of heat and pressure, comprising in combination a woven fabric backed member one surface of which is coated with a plurality of superimposed coatings, one of said coatings adhering to said backing member as an undercoat, another of said coatings adhering to said undercoat and comprising a surface coat, said surface coat having a softening point in the range of from about 240 degrees Fahrenheit to about 390 degrees Fahrenheit and consisting essentially of at least about six parts by weight of a vinyl chloride vinyl acetate c0- polymer including at least about eighty per cent by weight vinyl chloride and from about ten to about twenty per cent vinyl acetate; and a minor portion, not more than about four parts by weight of a compatible liquid plasticizer; and said undercoat consisting essentially of at least about six parts by weight of vinyl chloride vinyl acetate copolymer; and of a minor portion, not more than about four parts by weight of a compatible plasticizer, said undercoat being compatible with said surface coat and having a softening point from about twenty degrees Fahrenheit to about 100 degrees Fahrenheit higher than said surface coat.

4. As a new article of manufacture, a me d sheet adapted for the repairing of torn surfaces by adherence thereto under the influence of heat and pressure, comprising in combination a flexible woven fabric base one surface of which is coated with a plurality of superimposed coatings, one of said coatings adhering to said base member as an undercoat, another of said coatings adhering to said underooat and comprising a surface coat, said surface coat consisting essentially of at least about six parts by weight of a maleic modified vinyl chloride vinyl acetate copolymer including at least about eighty per cent by weight of vinyl chloride, from about ten to about twenty per cent of vinyl acetate and from about five tenths of one per cent to about five per cent of maleic acid; and of' a minor portion of liquid dioctyl phthalate plasti-cizer; said undercoat consisting essentially of at least about six parts by weight of a vinyl chloride vinyl acetate copolymer including about nine parts b weight of vinyl chloride and about one part by weight of vinyl acetate, and of a minor portion, not more than about four parts by weight, of compatible plasticizer, said undercoat being compatible with said surface coat and having a softening point between about twenty degrees Fahrenheit and about 100 degrees Fahrenheit higher than said surface coatmg.

5. As a new article of manufacture, a mending sheet adapted for the repairing of torn surfaces by adherence thereto under the influence of heat and pressure, comprising in combination a flexible woven fabric base one surface of which is coated with a plurality of superimposed coatings, one of said coatings adhering to said flexible woven fabric base as an undercoat, another of said coatings adhering to said undercoat and comprising a surface coat, said surface coat consisting essentially of at least about six parts by weight of a maleic modified vinyl chloride vinyl acetate c0- polymer including about eighty per cent by weight of vinyl chloride, fro-m about ten to about twenty per cent by weight of vinyl acetate and from about 0.5 to about five per cent by weight of maleic acid; and a minor Portion, not more than about four parts by weight of liquid compatible plasticizer; said surface coat having a relatively low softening point'in the range of from about 240 to about 300 degrees Fahrenheit; said undercoat consisting essentially of at least about six parts by weight of a polymeric, thermoplastic vinyl polymer, compatible with said surface coat, and having a softening point at least twenty degrees higher than the softening point of said surface coat.

MAX M. KLINE. CHARLES OLSON PIKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 997,125 Gleason July l, 1911 2,057,042 McLaurin Oct. 13, 1936 2,077,125 Miller et al Apr. 13, 1937 2,162,769 Williams June 20, 1939 2,329,456 Campbell Sept. 14, 1943 2,395,257 Didilian Feb. 19, 19 6 

1. AS A NEW ARTICLE OF MANUFACTURE, A MENDING SHEET ADAPTED FOR THE REPAIRING OF TORN SURFACES BY ADHERENCE THERETO UNDER THE INFLUENCE OF HEAT AND PRESSURE, COMPRISING IN COMBINATION A FLEXIBLE FABRIC BASE ONE SURFACE OF WHICH IS COATED WITH A PLURALITY OF SUPERIMPOSED COATINGS, ONE OF SAID COATINGS ADHERING TO SAID BASE MEMBER AS AN UNDERCOAT, ANOTHER OF SAID COATINGS ADHERING TO SAID UNDERCOAT AND COMPRISING A SURFACE COAT, SAID SURFACE COAT CONSISTING ESSENTIALLY OF AT LEAST ABOUT SIX PARTS BY WEIGHT OF VINYL CHLORIDE VINYL ACETATE COPOLYMER INCLUDING AT LEAST SIXTY-FIVE PER CENT BY WEIGHT OF VINYL CHLORIDE AND FROM ABOUT TEN TO ABOUT THIRTY PER CENT OF VINYL ACETATE; AND OF A MINOR PORTION, NOT EXCEEDING ABOUT FOUR PARTS BY WEIGHT OF THE SURFACE COAT COMPOSITION, OF A COMPATIBLE PLASTICIZER; SAID UNDERCOAT CONSISTING ESSENTIALLY OF AT LEAST ABOUT SIX PARTS BY WEIGHT OF A VINYL CHLORIDE VINYL ACETATE COPOLYMER INCLUDING AT LEAST SIXTY-FIVE PER CENT BY WEIGHT OF VINYL CHLORIDE AND FROM ABOUT TEN TO ABOUT THIRTY PARTS BY WEIGHT OF VINYL ACETATE; AND OF A MINOR PORTION, NOT EXCEEDING THIRTYSIX PER CENT BY WEIGHT OF THE UNDERCOAT, OF A COMPATIBLE PLASTICIZER; SAID UNDERCOAT BEING COMPATIBLE WITH SAID SURFACE COAT AND HAVING A SOFTENING POINT BETWEEN ABOUT TWENTY DEGREES FAHRENHEIT AND ABOUT 100 DEGREES FARENHEIT HIGHER THAN SAID SURFACE COATING. 